Romney, the national front-runner and a familiar face in Iowa after his 2008 presidential run, attracts support from 23 percent of likely Republican caucus-goers. Bachmann, who will officially kick off her campaign in Iowa on Monday, nearly matches him, with 22 percent.

“She’s up there as a real competitor and a real contender,” said Republican pollster Randy Gutermuth, who is unaffiliated with any of the presidential candidates. “This would indicate that she’s going to be a real player in Iowa.”

Former Godfather’s CEO Herman Cain, who has never held public office but has found a following among tea party supporters, comes in third, with 10 percent.

The other candidates tested register in single digits: former U.S. Speaker of the House Newt Gingrich and Texas Rep. Ron Paul, 7 percent each; former Minnesota Gov. Tim Pawlenty, 6 percent; former Pennsylvania Sen. Rick Santorum, 4 percent; and former Utah Gov. and ambassador to China Jon Huntsman, 2 percent.

Pawlenty has spent 26 days in Iowa during this election cycle, has hired an A-list team of Iowa campaign operatives and was the first major candidate to air television ads in Iowa.

“If I were the Pawlenty camp, I would be enormously concerned about this poll,” said Jennifer Duffy of the nonpartisan Cook Political Report.

The Des Moines Register’s Iowa Poll is a closely watched indicator of political viability in the leadoff caucus state in the presidential nominating process. The Iowa caucuses are scheduled for Feb. 6.

Veteran campaign watchers caution that it’s early: Candidates’ fortunes will rise and fall. Indeed, 69 percent of respondents said they could still be persuaded to support a candidate other than their first choice.

The poll, conducted by Selzer & Co. Inc. of Des Moines, was based on telephone interviews with 400 likely Republican caucus-goers June 19 to 22. The margin of error is plus or minus 4.9 percentage points.